#include <stdio.h>
int main() {
    int n, x, y, ans;
    scanf_s("%d%d%d", &n, &x, &y);
    if (y % x == 0)ans = n - y / x;
    else ans = n - y / x - 1;
    if (ans < 0)
        printf("0");
    else
        printf("%d", ans);
    return 0;
}